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on the underlying cause , but most patients with Bell ’ s palsy recover well within several weeks to months . Patients with other aetiologies of facial nerve palsy may have a different prognosis . 19
Management of chronic flaccid facial paralysis
Loss of facial muscle function over time
results in laxity and drooping of the affected side of the face . Additionally , difficulties with speech , eye closure and eating can arise , which , along with facial deformity , often lead to social isolation and depression . Restoration of symmetry and function using surgical techniques are associated with improvement in quality-of-life scores . 20
Key determinants of management for flaccid facial paralysis are the duration and degree of facial paralysis . Longer duration of paralysis affects the reinnervation potential of the facial musculature and distal facial nerve branches . Patients presenting less than two years from onset of flaccid facial paralysis are considered candidates for reinnervation of native facial musculature . 21
The hypoglossal , spinal accessory ,
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facial , and motor branches of the trigeminal ( V3 ) nerve , have been used to restore facial tone and movement . 22-25
In patients with longstanding flaccid paralysis , regional and free tissue transfer may be used to improve symmetry and regain their smile ( see figure 1 ). Temporalis muscle transfer is a common procedure in patients who are not willing to undergo microsurgical procedures . Microvascular free muscle transfer is the gold standard procedure for dynamic reanimation . Currently , the most commonly used muscle is the gracilis , as complications at its donor site are minimal , and no functional deficit is incurred . 26
Management of non-flaccid facial paralysis and synkinesis
Synkinesis represents a delayed complication
of facial nerve paralysis characterised by involuntary activation of specific facial muscles with voluntary facial movement . 27
Synkinesis typically arises at least four months post-onset and may be delayed until up to 40 months later . It is generally accepted that this occurs because , when axons at the proximal end
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of the injured facial nerve regrow , collateral sprouting can lead to a single axon ultimately innervating multiple peripheral facial nerve branches .
28 , 29
Botulinum toxin represents a therapeutic cornerstone for facial asymmetry and synkinesis among patients with facial nerve paralysis . Synkinetic activity may distort the appearance of a voluntary smile due to concurrent activation of antagonist muscles including the depressor anguli oris , mentalis and platysma ( see figure 2 ). These muscles may also be systematically targeted with chemodenervation to produce a more open , natural smile . Chemodenervation is considered first-line therapy , is minimally invasive , and temporary , with minimal adverse effects . 30 In Australia , botulinum toxin is PBS-listed for treatment of hemifacial spasm and blepharospasm , and represents an affordable and effective treatment for patients with non-flaccid facial paralysis . 31
Surgical intervention for facial synkinesis is typically reserved for patients with longstanding symptoms . The goals of surgery include restoration of facial symmetry and addressing functional deficits . 27 Myectomy , facial repositioning
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and selective neurolysis may all have a role , separately or in combination . Given the variable course experienced by patients with facial nerve paralysis , a multidisciplinary and multimodal approach is often warranted to optimise individual outcomes . 32
Conclusion
Facial palsy is a challenging condition that requires a comprehensive approach to diagnosis and management . GPs play a vital role in the early evaluation and treatment of patients with facial palsy , often collaborating with specialists to optimise outcomes , particularly for patients for whom recovery is delayed or incomplete . Understanding contemporary management strategies allows GPs to offer the best care to their patients and support them in maximising their recovery .
References on request from kate . kelso @ adg . com . au
Online resource
facialpalsy . org . uk
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